Assume you abort revdep-rebuild with Ctrl-C, change something and want to start over. Now the cache may be out of date. Instead of manually going to /var/cache/revdep-rebuild/ and removing the files, there should be an option that just does that before revdep-rebuild runs.
Does the '-i' option not do what you want?
There already is: -i | --ignore Delete temporary files from previous runs.
Ah!